Adhesion between chemical vapor deposition (CVD) barrier dielectric layers, or via etch-stop layers, and silicate (SiO based materials) low-k films, or solution-gelation (SOL-GEL) processed films, is a major concern in microelectronics integration. Weak adhesion at this interface results in film delamination during subsequent processing. In current practice, such adhesion is very low, on the order of less than about 0.12 GPa/M (giga parcel/square root meter), which results in severe peeling.
U.S. Pat. No. 6,303,524 B1 to Sharangpani et al. describes low-k curing methods that affect adhesion.
U.S. Pat. No. 6,303,523 B2 to Cheung et al. describes a low-k film deposition process to improve adhesion.
U.S. Pat. No. 6,180,518 B1 to Layadi et al. describes a method of forming vias in a low-k dielectric material and discusses low-k layer adhesion problems.
U.S. Pat. No. 4,238,528 to Angelo et al. describes adhesion promoters for polyamides.
U.S. Pat. No. 5,965,202 to Taylor-Smith et al. describes coupling agents between low-k layers.
Accordingly, it is an object of one or more embodiments of the present invention to provide enhanced adhesion between dielectric films and silicate films.
It is another object of one or more embodiments of the present invention to provide enhanced adhesion between CVD dielectric films and spin-on low-k silicate films.
Other objects will appear hereinafter.
It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, a structure having an overlying dielectric layer formed thereover is provided. An adhesion promoter layer is formed upon the dielectric layer. The adhesion promoter layer including adhesion promotion molecules. The dielectric layer and the adhesion promoter layer are treated to a low-temperature treatment to bind at least some of the adhesion promotion molecules to the dielectric layer. A silicate layer is formed upon the low-temperature treated adhesion promoter layer. The silicate layer and the low-temperature treated adhesion promoter layer are treated to a high-temperature treatment to bind at least some of the adhesion promotion molecules to the silicate layer whereby the silicate layer is adhered to the dielectric layer.